UN staff members take part in a protest demanding more decent working conditions, at the UN headquarters in New York, on May 1, 2013. (Xinhua/Niu Xiaolei)

UN staff members take part in a protest demanding more decent working conditions, at the UN headquarters in New York, on May 1, 2013. (Xinhua/Niu Xiaolei)

 UN staff members take part in a protest demanding more decent working conditions, at the UN headquarters in New York, on May 1, 2013. (Xinhua/Niu Xiaolei)

UN staff members take part in a protest demanding more decent working conditions, at the UN headquarters in New York, on May 1, 2013. (Xinhua/Niu Xiaolei)

A demonstrator holding a banner on a statue attends the annual May Day demonstration in Paris, France, May 1, 2013. (Xinhua/Etienne Laurent)

 A demonstrator holding a banner on a statue attends the annual May Day demonstration in Paris, France, May 1, 2013. (Xinhua/Etienne Laurent)

Demonstrators march in the annual May Day demonstration in Paris, France, May 1, 2013. (Xinhua/Etienne Laurent)

Demonstrators march in the annual May Day demonstration in Paris, France, May 1, 2013. (Xinhua/Etienne Laurent)

Jean-Luc Melenchon, French left Parti de Gauche party leader, attends the annual May Day demonstration in Paris, France, May 1, 2013. (Xinhua/Etienne Laurent)

A demonstrator holding a banner on a statue attends the annual May Day demonstration in Paris, France, May 1, 2013. (Xinhua/Etienne Laurent)

Demonstrators march in the annual May Day demonstration in Paris, France, May 1, 2013. (Xinhua/Etienne Laurent)

Demonstrators march in the annual May Day demonstration in Paris, France, May 1, 2013. (Xinhua/Etienne Laurent)

Demonstrators march in the annual May Day demonstration in Paris, France, May 1, 2013. (Xinhua/Etienne Laurent)

An Egyptian worker carries anti-Government panel during a protest in Tahrir square marking the world Labour day in Cairo, May 1, 2013. Dozens of national factories and companies were sold to the private sector during Hosni Mubarak's regime causing unemployment of thousands of Egyptian workers whom still lacking proper work today. (Xinhua/Amru Salahuddien)

Egyptian workers and activists chant anti-Government slogans during a protest in Tahrir square marking the world Labour day in Cairo, May 1, 2013. Dozens of national factories and companies were sold to the private sector during Hosni Mubarak's regime causing unemployment of thousands of Egyptian workers whom still lacking proper work today. (Xinhua/Amru Salahuddien)